EMILE/second/switch_to_PPC.S
2007-03-22 15:36:39 +00:00

83 lines
1.1 KiB
ArmAsm

/*
*
* (c) 2005-2007 Laurent Vivier <Laurent@lvivier.info>
* from BootX, (c) Benjamin Herrenschmidt
*
*/
.cpu 68020
.equ PC, 0x00FC
.equ GPR, 0x0100
.equ FPR, 0x0200
#define pc %sp@(PC)
#define gpr(a) %sp@(GPR + 8 * a + 4)
#define fpr0(a) %sp@(FPR + 8 * a)
#define fpr1(a) %sp@(FPR + 8 * a + 4)
.macro copy_PC
move.l %a1@+, pc
.endm
.macro copy_GPR from=0, to=31
move.l %a1@+, gpr(\from)
.if \to-\from
copy_GPR "(\from+1)",\to
.endif
.endm
.macro copy_FPR from=0, to=31
move.l %a1@+, fpr0(\from)
move.l %a1@+, fpr1(\from)
.if \to-\from
copy_FPR "(\from+1)",\to
.endif
.endm
.macro _EnterPPC
move.l #0x47617279, %a0 /* 'Gary' */
move.l #0x05051956, %a1
move.l #0x0000C000, %d0
moveq #0, %d2
reset
move.l %sp,-(%sp)
0:
dc.w 0xFE03
beq 0b
.endm
.align 4
.global switch_to_PPC
switch_to_PPC:
link.w %fp,#0
/* get PPC registers values */
move.l 8(%fp), %a1
/* prepare stack */
move.l %sp, %d0
andi.l #0xFFFFFC00, %d0
move.l %d0, %sp
move.l #0x00BF, %d0
loop:
clr.l -(%sp)
dbra %d0, loop
/* Initialize PPC registers */
copy_PC
copy_GPR
copy_FPR
/* Switch to PPC */
_EnterPPC
unlk %fp
rts